Here's a brand of which I'm not familiar with. The amount of different companies/brands that pushed out Engineer Boots back in the day is insane.

Notice the arching instep strap at the base, under the buckle. This is reminiscent of the style used on Knapp Engineer Boots and also is the basis for the Mister Freedom Road Champ Engineer Boots. The seller claims the soles are not original - if so, definitely a period replacement. I'd have to agree with the seller on the circa "60's." Not a bad price.